: Wood and Forest by Noyes William - Forests and forestry; Wood

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U. S. Department of Agriculture Year Books for:

U. S. Department of Agriculture, Division of Entomology Bulletins:

U. S. Department of Agriculture, Bureau of Plant Industry, Bulletins:

THE STRUCTURE OF WOOD.

When it is remembered that the suitability of wood for a particular purpose depends most of all upon its internal structure, it is plain that the woodworker should know the essential characteristics of that structure. While his main interest in wood is as lumber, dead material to be used in woodworking, he can properly understand its structure only by knowing something of it as a live, growing organism. To facilitate this, a knowledge of its position in the plant world is helpful.

All the useful woods are to be found in the highest sub-kingdom of the plant world, the flowering plants or Phanerogamia of the botanist. These flowering plants are to be classified as follows:

Under the division of naked-seeded plants , practically the only valuable timber-bearing plants are the needle-leaved trees or the conifers, including such trees as the pines, cedars, spruces, firs, etc. Their wood grows rapidly in concentric annual rings, like that of the broad-leaved trees; is easily worked, and is more widely used than the wood of any other class of trees.

Of fruit-bearing trees , there are two classes, those that have one seed-leaf as they germinate, and those that have two seed-leaves.

The most useful of the monocotyledons, or endogens, are the bamboos, which are giant members of the group of grasses, Fig. 1. They grow in dense forests, some varieties often 70 feet high and 6 inches in diameter, shooting up their entire height in a single season. Bamboo is very highly valued in the Orient, where it is used for masts, for house rafters, and other building purposes, for gutters and water-pipes and in countless other ways. It is twice as strong as any of our woods.

Under the fruit-bearing trees , timber trees are chiefly found among those that have two seed-leaves and include the great mass of broad-leaved or deciduous trees such as chestnut, oak, ash and maple. It is to these and to the conifers that our principal attention will be given, since they constitute the bulk of the wood in common use.

The timber-bearing trees, then, are the:

Conifers, the needle-leaved, naked-seeded trees, such as pine, cedar, etc. Fig. 45, p. 199.

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